Search results
Results from the WOW.Com Content Network
Phenolphthalein (/ f ɛ ˈ n ɒ l (f) θ ə l iː n / [citation needed] feh-NOL(F)-thə-leen) is a chemical compound with the formula C 20 H 14 O 4 and is often written as "HIn", "HPh", "phph" or simply "Ph" in shorthand notation. Phenolphthalein is often used as an indicator in acid–base titrations.
The Kastle–Meyer test is a presumptive blood test, first described in 1903, in which the chemical indicator phenolphthalein is used to detect the possible presence of hemoglobin. It relies on the peroxidase -like activity of hemoglobin in blood to catalyze the oxidation of phenolphthalin (the colorless reduced form of phenolphthalein) into ...
Three different points in an acid-base titration using phenolphthalein as the indicator Phenolphthalein is widely recognized as one of the most commonly used acid-base indicators in chemistry. [ 12 ] Its popularity is because of its effectiveness in a broad pH range and its distinct colour transitions. [ 12 ]
The meter reading (in millivolts) is plotted against the volume of titrant. The end point is taken at the distinct inflection of the resulting titration curve corresponding to the basic buffer solution. Color indicating titration: An appropriate pH color indicator e.g. phenolphthalein, is used. Titrant is added to the sample by means of a burette.
Moreover, pH indicators form one of the three main types of indicator compounds used in chemical analysis. For the quantitative analysis of metal cations, the use of complexometric indicators is preferred, [ 2 ] [ 3 ] whereas the third compound class, the redox indicators , are used in redox titrations ( titrations involving one or more redox ...
In Klein’s case, a Postal Service spokeswoman said, the problem is the road. Hillman Ridge is paved but narrows to a width slightly larger than a pickup truck as it approaches Klein’s property.
Scientists have developed two methods to measure the amount of basic sites: one, titration with benzoic acid using indicators and gaseous acid adsorption. [15] A solid with enough basic strength will absorb an electrically neutral acidic indicator and cause the acidic indicator's color to change to the color of its conjugate base. [ 15 ]
WASHINGTON (Reuters) -The U.S. government posted a $367 billion budget deficit for November, up 17% from a year earlier, as calendar adjustments for benefit payments boosted outlays by some $80 ...